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Show CURIOUS DEVICES USED FOR SEEING AFTER DARKNESS It is presumed that man originally origi-nally toiled or played only during hours of sunlight. That when darkness dark-ness came and the eyes could no longer see he lay himself down to rest. Yet all the while, Nature, through volcanic and meteoric disturbances, through flashes of lightning, was trying to demonstrate demon-strate to man its power to create light in the midst of darkness. Fire was discovered, and man found he could prolong the day with the aid of firebrands, camp fires, torches. The earliest lamps of which we have record were saucer shaped objects with a shallow projecting spout which held the wick. A hole in the center of this disc-like lamp held a small quantity of oil. So far as is known, there was no radical development toward better lighting until 1783 A. D., when Leger of Paris devised a flat ribbon wick and burner. Not long after, Ami Argand of Paris, perfected a glass chimney which, together with his new improved type of circular wick and burner, produced illumination far superior supe-rior to anything ever before seen. Then in 18 80, Auer von Welsbach, a German, developed a burner, in which the combination of a mixture of air and gas or vapor, heated to incandescence a mantle, composed of thoria and ceria. Welsbach's mantle was, of course, crude and inefficient compared com-pared to present-day mantles. But to Welsbach, should go much of the credit for making available to us today, the pure white light which is so easily and economically economi-cally provided in modern pressure mantle lamps using gasoline and kerosene for fuel. |